Flaxseed and flaxseed oil: one plant, two different foods

In a meta-analysis of 33 randomized trials with 2427 people, flaxseed products lowered systolic blood pressure by 3.2 mmHg and diastolic by 2.6 mmHg, with bigger drops at 30 g a day or more. The trials disagreed sharply with each other, and ground seed, oil and lignan supplements were pooled together. Flaxseed oil on its own is barely tested. A meta-analysis of 17 trials of olive and flaxseed oil, only 3 of them on flaxseed oil, found no effect on systolic pressure, a mean difference of minus 0.48 mmHg (95% CI minus 1.76 to 0.80). The two foods differ on the label as well. Ground seed averages 19.4 g of alpha-linolenic acid (ALA) and 23.1 g of fiber per 3.5 oz (100 g). The oil carries 53 g of ALA and no fiber, about 7.5 g of ALA in a 14 g tablespoon. Ground raw seed also releases cyanide, and at the worst-case level in EU data about 4 g, roughly a teaspoon, takes a toddler past the EU acute limit.

How much is actually in it

• Across 8 analyzed samples of ground flaxseed, alpha-linolenic acid ranged from 5.6 to 23.5 g and fiber from 18.6 to 36.7 g per 3.5 oz (100 g). — USDA FoodData Central Foundation Foods, Flaxseed, ground, 8 samples, release 2026-04-30 (n = 8 samples) Evidence E source
  ALA mean 19.4 g (5.56 to 23.48), total fat mean 37.3 g (11.7 to 42.3), fiber mean 23.1 g (18.6 to 36.7), protein mean 18.0 g per 3.5 oz (100 g)
• Flaxseed oil carries 1.9 oz (53 g) of alpha-linolenic acid per 3.5 oz (100 g) in the US survey database, about 2.7 times the mean of ground seed, and no fiber. — USDA FNDDS 2021-2023, Flaxseed oil, food code 82103500, fdc_id 2710185 Evidence E source
  ALA 53.4 g per 3.5 oz (100 g) of oil vs mean 19.4 g per 3.5 oz (100 g) ground seed

What a real portion looks like

• One tablespoon of flaxseed oil (14 g) gives about 7.5 g of alpha-linolenic acid in the US survey database. — USDA FNDDS 2021-2023, fdc_id 2710185, portion 1 tablespoon 14 g Evidence E source
  1 tablespoon 14 g, ALA 7.5 g

What your body absorbs

• In a 4-week randomized trial giving 6 g of alpha-linolenic acid a day, flaxseed oil raised plasma ALA and EPA in all subjects, while 1.1 oz (30 g) of ground seed raised ALA significantly only in those aged 18 to 29. — adults aged 18-29 or 45-69 years, 4 weeks, 6 g ALA a day as 30 g ground flaxseed or flaxseed oil Evidence B source
  Plasma ALA and EPA up in all oil groups; ground seed significant only in the younger group
• In a 30-day randomized trial in 34 adults, 10 g of milled flaxseed a day raised plasma ALA and enterolignans, but only 30 g a day raised EPA. — 34 healthy adults aged 18-49, one muffin a day with 10, 20, 30 or 40 g milled flaxseed for 30 days (n = 34) Evidence B source
  Plasma ALA rose at all doses except 20 g (no dose-response, P = 0.81); EPA rose only at 30 g/day (P = 0.047)
• In the human study EFSA relies on, 1.1 oz (30.9 g) of linseed carrying 6.8 mg of cyanide raised blood cyanide far less than cassava with the same amount, a mean peak of 6.40 against 16.95 µM. EFSA explains this by weaker seed enzymes and judges its acute limit likely over-conservative for foods such as linseed. — human volunteers in the bioavailability study EFSA relies on Evidence E source
  30.9 g linseed with 6.8 mg cyanide gave a mean blood cyanide peak of 6.40 µM against 16.95 µM for cassava with the same dose; cyanide released more slowly because of lower beta-glucosidase activity; ARfD likely over-conservative for linseed
• In a 30-day trial in 34 healthy adults eating a muffin with 10, 20, 30 or 1.4 oz (40 g) of milled flaxseed a day, no adverse events were reported at any dose and platelet aggregation did not change. Only the 30 g dose raised blood EPA. — healthy, younger adults aged 18 to 49 years (n = 34) Evidence B source
  10, 20, 30 or 40 g/day milled flaxseed in a muffin for 30 days: no reported adverse events and no change in platelet aggregation at any dose; only 30 g/day raised EPA

What cooking and storage change

• Since 2022 EU law caps hydrocyanic acid at 150 mg per kg in whole or ground linseed sold to consumers and 250 mg per kg in other linseed. It gives the reason that ground linseed eaten raw releases more cyanide than whole or heat-treated seed. — linseed placed on the EU market Evidence E source
  Hydrocyanic acid at most 150 mg/kg in linseed sold to the final consumer and 250 mg/kg in other linseed; stricter because ground raw linseed releases more; exemption for small packs labeled 'Only to be used for cooking and baking. Do not consume raw!'

What it does to your health

• A meta-analysis of 33 randomized trials in 2427 people found flaxseed products lowered systolic blood pressure by 3.2 mmHg and diastolic by 2.6 mmHg, more at 30 g a day or above. — 33 trials, 43 arms, 2427 participants (n = 2427) Evidence A source
  Systolic -3.19 mmHg (95% CI -4.15 to -2.24); diastolic -2.61 mmHg (95% CI -3.27 to -1.94)
• A meta-analysis of 17 randomized trials of olive and flaxseed oil, only 3 of them flaxseed oil, found no effect on systolic blood pressure, mean difference -0.48 mmHg. — 17 RCTs in normotensive or at-risk adults, 14 on olive oil and 3 on flaxseed oil capsules (n = 17 trials) Evidence A source
  Systolic MD -0.48 mmHg (95% CI -1.76 to 0.80); diastolic MD -0.47 mmHg; CRP no change
• A meta-analysis of 64 randomized trials found flaxseed supplements cut body weight by 1.4 lb (0.63 kg) and waist by 0.55 in (1.4 cm), with moderate certainty. — 64 trials, 72 treatment arms, lignans, whole flaxseed and flaxseed oil (n = 64 trials) Evidence A source
  Body weight -1.4 lb (95% CI -2.2 to -0.6; metric: -0.63 kg, -1.00 to -0.27); BMI -0.24 kg/m2; waist -0.56 in (95% CI -0.81 to -0.31; metric: -1.43 cm, -2.06 to -0.80)
• A meta-analysis of 54 randomized trials in 3000 adults found flaxseed lowered C-reactive protein, standardized mean difference -0.46, but not TNF-alpha. — 54 RCTs, 3000 individuals from 12 countries (n = 3000) Evidence A source
  CRP SMD -0.46 (95% CI -0.70 to -0.23); IL-6 SMD -0.64; TNF-alpha SMD -0.17 (ns)
• In people with overweight or obesity, a meta-analysis of 19 randomized trials in 1183 people found ALA from flaxseed and other plants lowered triglycerides and systolic pressure but slightly raised LDL cholesterol. — 19 RCTs, 1183 adults with overweight or obesity (n = 1183) Evidence A source
  Triglycerides SMD -4.41; systolic SMD -0.37; LDL cholesterol SMD +1.32 (95% CI 0.05 to 2.59)

Safety, limits and interactions

• A systematic review of 1491 documented supplement and drug interactions found flaxseed among the three supplements with the most documented contraindications. — 85 primary studies, six books and two websites; 213 supplement entities and 509 medications (n = 1491 pairs) Evidence C source
  Flaxseed, echinacea and yohimbe had the largest number of documented contraindications
• Flaxseed allergy is documented mainly through case reports, and a review of edible seed allergies found severe reactions possible, with seed oils also covered as exposure routes. — English literature 1930 to March 2016 on sesame, sunflower, poppy, pumpkin, flax and mustard seed hypersensitivity Evidence D source
  No prevalence estimate for flaxseed; sesame allergy estimated at 0.1 to 0.2%
• The US National Center for Complementary and Integrative Health says there are theoretical reasons to suspect flaxseed or flaxseed oil might interact with anticoagulant or antiplatelet drugs, and advises anyone on medicines to ask their doctor first. — people taking anticoagulant or antiplatelet drugs Evidence E source
  Theoretical interaction with anticoagulant or antiplatelet drugs; advice to talk with a health care provider
• NCCIH says limited amounts of flaxseed or flaxseed oil may be safe for up to 6 months, that higher doses may cause bloating, fullness and diarrhea, and that raw or unripe seeds should not be eaten because they may contain potentially toxic compounds. — adults using flaxseed or flaxseed oil supplements Evidence E source
  Limited amounts may be safe short term (up to 6 months); higher doses may cause bloating, fullness and diarrhea; raw or unripe seeds may contain potentially toxic compounds

What people believe that the data does not support

• The EU rejected the claim that flaxseed oil or its alpha-linolenic acid promotes heart health. — EU Register on nutrition and health claims, claim POL-HC-7106 Evidence E source
  Status non-authorized
• The EU rejected the claim that flaxseed oil stabilizes mood. — EU Register on nutrition and health claims, claim POL-HC-7105 Evidence E source
  Status non-authorized

Who this works differently for

• In a 4-week randomized trial in 32 children aged 8 to 18 with high cholesterol, 1.1 oz (30 g) of ground flaxseed a day lowered HDL cholesterol by 15 percent and raised triglycerides by 26 percent without lowering LDL. — 32 children and adolescents aged 8-18 with LDL 135 to <193 mg/dL, 4 weeks, 30 g ground flaxseed in muffins and bread (n = 32) Evidence B source
  HDL -7.35 mg/dL (-15%, 95% CI -24% to -6%); triglycerides +29.23 mg/dL (+26%, 95% CI +4% to +48%); LDL -6.96 mg/dL (ns)
• For ground linseed at the highest cyanide level in the EFSA database, 407 mg per kg, EFSA calculates that 1.3 to 14.7 g in one eating occasion reaches the acute limit of 20 mcg cyanide per kg body weight. At average body weight that is about 1.7 g for a toddler and 10.9 g for an adult. EFSA expects whole, unground seeds to give much lower exposure. — toddlers to adults, by body weight, EU back-calculation Evidence E source
  Ground linseed at 407 mg CN/kg reaches the ARfD at 1.3 to 14.7 g per eating occasion; at mean body weight 1.7 g for toddlers, 3.4 g for other children, 6.4 g for young adolescents, 9.0 g for adolescents, 10.9 g for adults
• EFSA notes that at the worst-case cyanide level a toddler would exceed the acute limit with about 4 g of ground linseed, roughly a teaspoon. It adds that a risk for adolescents cannot be excluded if linseed is ground, for example in a blender, and eaten at the 10 to 15 g three times a day that EMA recommends for constipation. — toddlers and adolescents, EU risk assessment Evidence E source
  Toddler exceeds the ARfD with about 4 g of ground linseed (a teaspoon) at the worst-case level; a risk for adolescents cannot be excluded at the EMA laxative dose of 10 to 15 g three times a day if the linseed is ground
• NCCIH says some studies suggest flaxseed is possibly unsafe in pregnancy, though the evidence is not conclusive, and that little is known about flaxseed while breastfeeding or about flaxseed oil in pregnancy or breastfeeding. — pregnant and breastfeeding women Evidence E source
  Flaxseed in pregnancy possibly unsafe, evidence not conclusive; safety of flaxseed in breastfeeding and of flaxseed oil in pregnancy or breastfeeding largely unknown

What is still unknown

• EFSA reports that the food agency of Australia and New Zealand judged linseed foods not an appreciable risk, even though some exposure estimates passed the acute limit. Its reasons were that no human poisonings from linseed are reported and that volunteers who ate 3.5 oz (100 g) of ground linseed had no detectable blood cyanide. — Australia and New Zealand, FSANZ assessment as reported by EFSA Evidence E source
  High linseed bread intake gave estimates above the ARfD, yet no reported human poisonings from linseed; no blood cyanide after 100 g ground linseed in volunteers

The bottom line

The seed samples varied widely, from 5.6 to 23.5 g of ALA per 3.5 oz (100 g), and the low end looks like a partly defatted product. The oil got ALA into the blood more reliably. At 6 g of ALA a day for 4 weeks, oil raised plasma ALA and EPA in everyone, while 1.1 oz (30 g) of ground seed did so significantly only in people aged 18 to 29, and the abstract does not say how many took part. In 34 younger adults eating flaxseed muffins for 30 days, 10 g a day was enough to raise ALA, and EPA rose only at 30 g, in groups of about eight. Across 64 randomized trials of seed, oil and lignans, body weight fell by 1.4 lb (0.63 kg) and waist by 0.55 in (1.4 cm), with moderate certainty. Across 54 trials in 3000 adults, C-reactive protein fell by a standardized mean difference of 0.46, TNF-alpha did not change, and the trials disagreed strongly. In 19 trials in people with overweight or obesity, ALA from flaxseed and other plants lowered triglycerides and systolic pressure and slightly raised LDL cholesterol (95% CI 0.05 to 2.59), reported in units that are hard to interpret. The EU refused two claims for flaxseed oil, that its ALA promotes heart health and that it stabilizes mood, because the evidence fell short when assessed. Children are the clearest caution. In 32 children aged 8 to 18 with high cholesterol, 1.1 oz (30 g) of ground flaxseed a day for 4 weeks lowered HDL cholesterol by 15 percent (95% CI 6 to 24) and raised triglycerides by 26 percent, and LDL did not fall significantly. Ground raw seed also carries compounds that release cyanide. At the highest cyanide level in the EFSA database, a toddler would pass the EU acute limit with about 4 g of ground linseed, roughly a teaspoon, and an adult of average weight with about 10.9 g in one sitting. EFSA adds that a risk for adolescents cannot be excluded at the laxative dose of 10 to 15 g three times a day if the seed is ground. It also calls that limit likely over-conservative for linseed, because in volunteers 1.1 oz (30.9 g) of linseed raised blood cyanide far less than cassava with the same dose, and it reports that the Australia and New Zealand food agency found no human poisonings from linseed. Since 2022 EU law caps cyanide in linseed sold to consumers at 150 mg per kg, because ground raw seed releases more than whole or heat-treated seed. That is a market limit, not a safe daily amount. In 34 healthy adults aged 18 to 49, up to 1.4 oz (40 g) of milled flaxseed a day baked into a muffin for 30 days caused no reported adverse events and did not change platelet aggregation, in groups of about eight. The US National Center for Complementary and Integrative Health (NCCIH) says limited amounts may be safe for up to 6 months, that higher doses may cause bloating, fullness and diarrhea, and that raw or unripe seeds should not be eaten. It names a theoretical interaction with anticoagulant and antiplatelet drugs and advises anyone on medicines to ask their doctor first. A review of documented supplement and drug interactions put flaxseed among the three supplements with the most listed contraindications. That counts mentions in the literature, not how often harm happens, and the abstract does not name the drugs. NCCIH says some studies suggest flaxseed is possibly unsafe in pregnancy, though the evidence is not conclusive, and that little is known about flaxseed in breastfeeding or about the oil in pregnancy or breastfeeding. Flaxseed allergy is known mainly from case reports, severe reactions are possible, and the review gives no estimate of how common it is.

Sources

1. fxfo-daily-r7-01 · reference dataset
   Foundation Flaxseed, ground: PUFA 18:3 n-3 c,c,c 19.42 G range 5.559-23.48, 8 samples · Total lipid (fat) 37.28 G range 11.69-42.29 · Fiber, total dietary 23.13 G range 18.6-36.7 · Protein 18.0359 G range 14.204-23.426
   USDA FoodData Central, Foundation Foods, release 2026-04-30 · checked 2026-09-29
2. fxfo-daily-r7-02 · reference dataset
   FNDDS 2710185 Flaxseed oil: PUFA 18:3 53.368 G/100 g
   USDA FNDDS 2021-2023 · checked 2026-09-29
3. fxfo-daily-r7-03 · reference dataset
   FNDDS 2710185 Flaxseed oil portions: 1 tablespoon 14 g · 1 cup 224 g; PUFA 18:3 53.368 G/100 g
   USDA FNDDS 2021-2023 · checked 2026-09-29
4. fxfo-daily-r7-04 · randomized trial
   To investigate the response, over a period of 4 weeks, of subjects aged 18-29 or 45-69 years to a diet containing the same amount of alpha-linolenic acid (ALA) (6 g) introduced in the form of ground flaxseed (30 g) or flaxseed oil. RESULTS: All subjects who received flaxseed oil showed a significant increase in plasma ALA and eicosapentaenoic acid (EPA) concentrations over the course of this study. Subjects who received ground flaxseed in the 18-29-year-old group showed a statistically significant increase in their plasma ALA levels, and although there was a trend in the same direction for the 45-69-year-old subjects, this did not achieve statistical significance.
   Eur J Clin Nutr, 2009 · checked 2026-09-29
5. fxfo-daily-r7-05 · randomized trial
   Healthy, younger adults (n = 34; 18-49 years old) were randomized into four groups consuming one muffin daily for 30 days fortified with 10, 20, 30 or 40 g of milled flaxseed. ... Only with the 30 g/day diet were n-3 polyunsaturated fatty acids (P = 0.007), and eicosapentaenoic acid (EPA) (P = 0.047) increased from baseline values. ... CONCLUSIONS: In healthy, younger adults, 10 g/day of milled flaxseed consumption is sufficient to significantly increase circulating ALA and total enterolignan concentrations; however, 30 g/day is required to convert ALA to EPA.
   Eur J Nutr, 2016 · checked 2026-09-29
6. hf2-fxfo-3 · EFSA scientific opinion
   In contrast, a lower bioavailability (peak level 6.5 μM after 60 min) was observed after ingestion of 30.9 g linseed also containing 6.8 mg cyanide. ... Linseed 6.40 ± 3.34 1.69–13.85 40 30–60 Apricot kernels 15.46 ± 5.12 7.48–22.59 20 5–40 Cassava 16.95 ± 5.96 10.31–31.87 30 22.5–52.5 ... The lower peak blood levels of cyanide observed after linseed as compared to cassava and apricot kernels containing equivalent amounts of bound cyanide can been explained by the lower activity of the degrading enzymes in linseed, in particular of the respective β‐glucosidase ... For exposure to cyanide from foods other than raw apricot kernels, bitter almonds and cassava roots, the release of cyanide is slower and the resultant blood levels are lower and the ARfD is likely to be over‐conservative.
   EFSA CONTAM Panel, Evaluation of the health risks related to the presence of cyanogenic glycosides in foods other than raw apricot kernels, EFSA Journal 2019;17(4):5662 · checked 2026-10-08
7. hf2-fxfo-8 · randomized controlled trial
   Healthy, younger adults (n = 34; 18-49 years old) were randomized into four groups consuming one muffin daily for 30 days fortified with 10, 20, 30 or 40 g of milled flaxseed. ... Flaxseed was well tolerated, even at the highest dose, as there were no reported adverse events, changes in cholesterol, platelet aggregation or urinary 11-dehydro-thromboxane B2.
   Eur J Nutr, 2016 · checked 2026-10-08
8. hf2-fxfo-5 · EU regulation
   When ground linseed as such is consumed, the bioavailability of hydrocyanic acid and human exposure levels to it are higher than when whole linseeds are consumed or when they are heat-treated. It is therefore appropriate to set stricter levels for whole linseed, which can be ground by the consumer, before consumption and ground linseed placed on the market for the final consumer when intended to be consumed raw. ... 8.3.2 Unprocessed whole, ground, milled, cracked, chopped linseed placed on the market for the final consumer ... 150 ... The maximum level does not apply to unprocessed whole, ground, milled, cracked, chopped linseed and unprocessed whole, ground, milled, cracked, chopped bitter almonds placed on the market for the final consumer in small quantities where the warning ‘Only to be used for cooking and baking. Do not consume raw!’ appears in the principal field of vision of the label
   Commission Regulation (EU) 2022/1364 of 4 August 2022, maximum levels of hydrocyanic acid in certain foodstuffs, OJ L 205/227 · checked 2026-10-08
9. fxfo-daily-r7-06 · meta-analysis of RCTs
   Meta-analysis of 33 trials (comprising 43 treatment arms) with 2427 participants revealed significant reductions in both systolic (WMD: -3.19 mmHg; 95% CI: -4.15 to -2.24, p < 0.001; I2 = 92.5%, p < 0.001) and diastolic blood pressure (WMD = -2.61 mmHg; 95% CI: -3.27, -1.94, p < 0.001; I2 = 94.1%, p < 0.001) following flaxseed supplementation. Greater effects on SBP and DBP were found in trials with an intervention duration of >20 weeks, ≥30 g day-1 of flaxseed, subjects with BMI 25-30 kg m-2, and in patients with hypertension.
   Food Funct, 2023 · checked 2026-09-29
10. fxfo-daily-r7-07 · meta-analysis of RCTs
    Seventeen RCTs, comprising 14 studies on OO and 3 on FLO, met the inclusion criteria. Meta-analysis using a random-effects model reported no significant effect on SBP n=17 mean difference (MD) -0.48; 95% CI: -1.76, 0.80; p=0.65, I2 =0%) and DBP (n=16, MD -0.47; 95% CI: -1.33, 0.39; p=0.65, I2 =0%)
    Curr Hypertens Rev, 2024 · checked 2026-09-29
11. fxfo-daily-r7-08 · meta-analysis of RCTs
    Sixty-four trials comprising 72 treatment arms were included. ... Our meta-analysis revealed significant reductions in body weight (WMD = -0.63 kg; 95 % CI: -1.00, -0.27, P < 0.001; I2 = 76.7 %, P < 0.001), body mass index (BMI) (WMD: -0.24 kg/m2, 95 % CI: -0.36, -0.11, P < 0.001; I2 = 78.5 %, P < 0.001) and waist circumference (WC) (WMD: -1.43 cm, 95 % CI: -2.06, -0.80, P < 0.001; I2 = 81.1 %, P < 0.001) following flaxseed supplementation.
    Complement Ther Med, 2024 · checked 2026-09-29
12. fxfo-daily-r7-09 · meta-analysis of RCTs
    The 54 RCTs were included in the final analysis, which involved 3000 individuals from 12 countries. Overall, the flaxseed supplementation had a significant reduction in C-reactive protein (CRP) (SMD = -0.46; 95 % CI: -0.70, -0.23, P < 0.001; I2 = 82.9 %, P < 0.001), and interleukin 6 (IL-6) (SMD = -0.64, 95 % CI: -1.13, -0.16, P = 0.010; I2 = 92.7, P < 0.001). Furthermore, flaxseed did not significantly change the concentration of tumor necrosis factor α (TNF-α) (SMD = -0.17; 95 % CI: -0.63, 0.29, P = 0.467; I2 = 92, P < 0.001).
    Prostaglandins Other Lipid Mediat, 2024 · checked 2026-09-29
13. fxfo-daily-r7-10 · meta-analysis of RCTs
    Nineteen eligible randomized controlled trials, including 1183 participants, were included in the meta-analysis. Compared with placebo, dietary ALA supplementation significantly reduced C-reactive protein concentration (standardized mean difference [SMD] = -0.38 mg/L; 95% confidence interval [CI]: -0.72, -0.04), tumor necrosis factor-α concentration (SMD = -0.45 pg/mL; 95% CI: -0.73, -0.17), triglyceride in serum (SMD = -4.41 mg/dL; 95% CI: -5.99, -2.82), and systolic blood pressure (SMD = -0.37 mm Hg; 95% CI: -0.66, -0.08); but led to a significant increase in low-density lipoprotein cholesterol concentrations (SMD = 1.32 mg/dL; 95% CI: 0.05, 2.59).
    Adv Nutr, 2023 · checked 2026-09-29
14. fxfo-daily-r7-12 · systematic literature review
    RESULTS: While 85 primary literatures, six books and two web sites were reviewed for a total of 1,491 unique pairs of HDS-drug interactions, 213 HDS entities and 509 medications were involved. ... Flaxseed, echinacea, and yohimbe had the largest number of documented contraindications.
    Int J Clin Pract, 2012 · checked 2026-09-29
15. fxfo-daily-r7-13 · literature review
    Several seeds have been increasingly incorporated in various food items, with consequent risk of hypersensitivity reactions that are often severe. ... Considering the worldwide consumption of those seeds, the number of published articles on the subject was relatively small and was mainly as case reports rather than large series. Allergy to sesame was more reported than to other seeds, with an estimated prevalence of 0.1-0.2%.
    Allergy, 2016 · checked 2026-09-29
16. hf2-fxfo-6 · agency advice
    There are theoretical reasons to suspect that flaxseed or flaxseed oil might interact with other drugs, such as anticoagulant or antiplatelet drugs. If you take any type of medicine, talk with your health care provider before using flaxseed, flaxseed oil, or other herbal products; some herbs and medicines interact in harmful ways.
    National Center for Complementary and Integrative Health (NIH), Flaxseed and Flaxseed Oil, What Do We Know About Safety? · checked 2026-10-08
17. hf2-fxfo-9 · agency advice
    Don’t eat raw or unripe flaxseeds; they may contain potentially toxic compounds. Limited amounts of flaxseed (especially flaxseed lignan extract or mucilage) or oral flaxseed oil supplements may be safe for use in the short-term (up to 6 months). Higher doses of flaxseed or flaxseed oil supplements may cause uncomfortable digestive symptoms like bloating, fullness, and diarrhea.
    National Center for Complementary and Integrative Health (NIH), Flaxseed and Flaxseed Oil, What Do We Know About Safety? · checked 2026-10-08
18. fxfo-daily-r7-14 · regulatory register
    POL-HC-7106 Flaxseed oil/alpha-linoleic acid Promotes heart health Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-7106, snapshot 2026-09-21 · checked 2026-09-29
19. fxfo-daily-r7-15 · regulatory register
    POL-HC-7105 Flaxseed oil Stabilises moods. Non-authorised
    EU Register on nutrition and health claims, claim POL-HC-7105, snapshot 2026-09-21 · checked 2026-09-29
20. fxfo-daily-r7-11 · randomized controlled trial
    Thirty-two participants aged 8 to 18 years with low-density lipoprotein cholesterol from 135 mg/dL (3.5 mmol/L) to less than 193 mg/dL (5.0 mmol/L). INTERVENTION: The intervention group ate 2 muffins and 1 slice of bread daily containing ground flaxseed (30 g flaxseed total). ... Dietary flaxseed supplementation resulted in an attributable decrease of -7.35 mg/dL (-0.19 mmol/L) in high-density lipoprotein cholesterol (95% CI, -3.09 to -11.60 mg/dL[-0.08 to -0.30 mmol/L]; relative: -15%, 95% CI, -24% to -6%; P = .001), an increase of 29.23 mg/dL (+0.33 mmol/L) in triglycerides (95% CI, 4.43 to 53.14 mg/dL [+0.05 to +0.60 mmol/L]; relative: +26%, 95% CI, +4% to +48%; P = .02)
    JAMA Pediatr, 2013 · checked 2026-09-29
21. hf2-fxfo-1 · EFSA scientific opinion
    Table 23 shows the estimated maximum amount of ground linseed that can be consumed without exceeding the ARfD of 20 μg/kg bw using the highest value reported in the EFSA database (407 mg CN/kg) as a worst‐case approach. Depending on the body weight of the individual, consumption of 1.3–14.7 g of ground, linseed containing CN at this level, reaches the ARfD ... It can be expected that consumption of intact linseed (i.e. not freshly ground) would lead to much lower cyanide exposures. ... Toddlers 8.7 11.9 15.9 407 a 3 0.02 1.3 1.7 2.3 Other children 14 23.1 37 407 a 3 0.02 2.1 3.4 5.5 Young adolescents 29.4 43.4 62 407 a 3 0.02 4.3 6.4 9.4 Adolescents 45 61.3 83 407 a 3 0.02 6.6 9.0 12.2 Adults 52 73.9 100 407 a 3 0.02 7.7 10.9 14.7
    EFSA CONTAM Panel, Evaluation of the health risks related to the presence of cyanogenic glycosides in foods other than raw apricot kernels, EFSA Journal 2019;17(4):5662 · checked 2026-10-08
22. hf2-fxfo-2 · EFSA scientific opinion
    ... recommends consumption of 10–15 g of linseed (whole or ‘broken’ linseed) three times a day to treat constipation in adults and adolescents aged over 12 years. For ground linseed containing the highest level of measured total CN levels (407 mg/kg) as a worst‐case scenario, the ARfD would be exceeded by a toddler when consuming about 4 g of ground linseed (roughly a tea spoon). Taking into account all uncertainties, a risk for adolescents cannot be excluded if ground linseed (e.g. when put in a blender) is consumed at the amount recommended by the EMA.
    EFSA CONTAM Panel, Evaluation of the health risks related to the presence of cyanogenic glycosides in foods other than raw apricot kernels, EFSA Journal 2019;17(4):5662 · checked 2026-10-08
23. hf2-fxfo-7 · agency advice
    Some studies of the use of flaxseed during pregnancy suggest it is possibly unsafe, but the evidence is not conclusive. Little is known about whether it is safe to use flaxseed while breastfeeding. Little is known about whether it is safe to use flaxseed oil during pregnancy or while breastfeeding.
    National Center for Complementary and Integrative Health (NIH), Flaxseed and Flaxseed Oil, What Do We Know About Safety? · checked 2026-10-08
24. hf2-fxfo-4 · EFSA scientific opinion
    Although acute exposures with linseed containing bread exceeded the ARfD, FSANZ concluded that linseed and foods containing linseed do not represent an appreciable health risk as there are not reports in the literature of human poisonings upon consumption of linseed and in a study in which human volunteers consumed 100 g of ground linseed no cyanide was detected in the blood
    EFSA CONTAM Panel, Evaluation of the health risks related to the presence of cyanogenic glycosides in foods other than raw apricot kernels, EFSA Journal 2019;17(4):5662 · checked 2026-10-08